THE MX NORTHERN ABELL CLUSTER REDSHIFT SURVEY

The results from the COBE satellite show the existence of structure on scales similar to 10% or more of the horizon scale of the universe. R ich clusters of galaxies from the Abell/Abell, Corwin, & Olowin catalo gs show evidence of structure on scales of 100 h(-1) Mpc and hold the promise of confirming structure on the scale of the COBE results. An i mpediment to that promise has been that redshift information has been unavailable for a large percentage of these clusters, so knowledge of their three-dimensional distribution has had large uncertainties. We h ave been working to greatly expand the sample of Abell clusters with r eliable redshifts. Our approach in this effort, through the MX Norther n Abell Cluster Redshift Survey, has been to measure redshifts of at l east 25 galaxies in each of 95 R greater than or equal to 1 Abell clus ter fields with m(10) less than or equal to 16.8 and zero or one previ ously measured redshift. Of these 95 observed Abell clusters, 88 new c luster redshifts were obtained with an average of nine cluster member galaxy redshifts per held. Two clusters were found to be chance projec tions of galaxies along the line of sight, while five cluster observat ions did not provide enough galaxy redshifts to make a positive identi fication. This work has resulted in a deeper, 98% complete, and more r eliable sample of three-dimensional positions of rich Abell clusters i n the northern hemisphere. The primary intent of this survey has been to produce a larger and more complete sample of rich Abell clusters th at can be used as tracers for large-scale structure. Through analyses with tools such as the two-point correlation function, power spectrum, and velocity dispersions, this sample can be used to constrain theore tical models better for the formation of structure we see in the unive rse today.